A popular way of shipping or storing records and files is in a container that consists of a drawer received in a casing. Such containers are widely marketed by the assignee of the present invention under the trademark "Transfile.RTM.." While containers of this type can be made of various sheet materials, such as plywood or fiberboard, they are usually made of corrugated boxboard. To enable easy access to the contents of the container, the casing is often made with an opening at one end so that the file drawer can be slid out. The opening is reinforced by metal reinforcing members.
The "Transfile.RTM." containers sold over many years have casings that are constructed in the manner shown in FIGS. 1 to 5 of the accompanying drawings. The construction is based in large part on an invention described and shown in U.S. Pat. No. 2,221,854 (Zalkind, Nov. 19, 1940). The casing 20 comprises a body 22 of corrugated boxboard having top and bottom walls 24 and 26, side walls 28 and 30 and an end wall at one end (not shown). It is produced as a onepiece blank with bending lines that facilitate erecting it from a flattened form in which it is shipped and stored. When erected for use (FIG. 1), it has an end opening 32 through which a drawer is inserted.
The opening 32 is shaped and rigidified against buckling by reinforcing elements in the form of channel- or U-shaped metal strips 34 that fit over the edges of the top and bottom walls 24, 26. The juncture between the two legs of the strip 34 is enlarged and receives the base portion of a U-shaped bar 36, only a portion of which is visible in FIG. 1. An arm at each end of each bar extends at a right angle to the base portion and extends into a corresponding reinforcing member 38, one of which fits over the edge of each of the two side walls 28 and 30 of the casing body at the opening 32. The bars 36 establish and maintain the rectangular shape of the casing opening. The reinforcing members 38 and elements 34, along with the bars in the case of the top and bottom walls, keep the walls of the casing from buckling at the opening.
The reinforcing elements and members are assembled onto the casing at the factory. The elements 34 are made and assembled onto the body in the condition in which they are shown in FIG. 1, except that the bars 36 are rotated, relative to the erected form, 90 degrees so that they lie in the planes of the top and bottom walls. The reinforcing members 38 are manufactured in the form shown in FIG. 4 and are assembled to the boxboard body in that form. The member 38 consists of an inner leg portion 40 that is substantially planar, but with a slight offset 42, and has a rolled bead 44 at its free end, which adds stiffness, presents an inset guide surface for the file drawer, and provides a smooth edge. An outer leg portion 46, which is also substantially planar, is formed with numerous punched prongs 48 that, in the assembled casing, pierce the casing body walls and are bent over and slightly out at their tips into the casing walls (to eliminate a sharp exposed tip) to secure the members to the body.
The juncture between the two leg portions 40 and 46 is formed by a flange portion 50 that is of a width slightly greater than that of the bars 36. Along each margin of the flange portion is a row of U-shaped slits 52 formed by slitting and bending in slightly small rectangular segments 54 of the metal band from which the member is formed. The longer portions of the slits--the portions that extend lengthwise of the member--define fold lines along which the inner leg portion of the member is folded by the user into the inside of the casing body when the casing is erected (see FIG. 3).
When the reinforcing member is properly folded over the edge of the casing wall, the respective leg portions should form right angles with the flange portion. Although the reinforcing member 38 shown in FIGS. 1 to 5 has served well over many years of widespread use, one of its shortcomings is that the user does not always form the fold at the flange properly. If one fold line is folded sharply, it becomes somewhat weaker than it should be, and it also presents a sharp edge. Moreover, the existence of the slits presents sharp corners, even when the member is folded correctly. The presence of the two fold lines also creates two lengthwise lines of weakness along the edge of the member, where the respective leg portions of the member are joined to the flange portion by only a series of relatively narrow, spaced-apart strands 56 of the metal between the ends of the adjacent slits.